T-Saw laminoplasty for the management of cervical spondylotic myelopathy: clinical and radiographic outcome.

STUDY DESIGN

Independent evaluation of 18 patients with multilevel cervical spondylotic myelopathy who underwent threadwire T-saw laminoplasty.

OBJECTIVES

Assess the efficacy of midline T-saw laminoplasty in non-Japanese patients based on clinical and radiographic criteria.

SUMMARY OF BACKGROUND DATA

Spinous process-splitting laminoplasty has been well accepted in Japan. The results in non-Japanese patients are unknown.

METHODS

A single physician performed independent clinical and radiographic evaluations at latest follow-up (mean, 24 months). In addition to a patient self-assessment questionnaire, objective measures included physical examination, Pavlov's ratio, sagittal canal diameter (by computed tomography), cord compression index, cervical lordosis, range of motion, and complications.

RESULTS

Progression of myelopathy was arrested in all patients. Patients reported improvement in strength (78%), dexterity (67%), numbness (83%), pain (83%), and gait (67%). Bowel and bladder compromise resolved in five of six patients. The mean Nurick score improved from 2.7 to 0.9 (P < 0.001), and the mean Robinson pain score improved from 2.0 to 0.89 (P = 0.002). No patient required narcotic analgesics at latest follow-up compared with eight before laminoplasty. Objectively, 68% of patients with motor weakness regained normal strength (P = 0.001), whereas 50% regained normal sensation (P = 0.003). Radiographic canal expansion was verified by a statistically significant increase in the mean Pavlov ratio and osseous sagittal computed tomographic measurements. The mean cord compression index improved from 0.49 to 0.61 (P = 0.01). There was no significant change in mean cervical lordosis. Graft dislodgment or segmental instability did not occur. Complications included: infection (n = 1) and persistent postoperative motor root lesion at C5 (n = 1).

CONCLUSIONS

T-saw laminoplasty appears to be a safe and effective method of arresting the progression of myelopathy and allowing marked functional improvement in most patients with multilevel cervical spondylotic myelopathy. [Key Words: cervical spine, decompression, laminoplasty, myelopathy, spondylosis]